1. Field of Invention
This invention relates to a lock for a door and more particularly to a lock having an alarm which is activated in response to an attempt to open the lock without a key.
2. Description of the Prior Art
A lock for a door is typically comprised of a tumbler assembly having a keyhole which is adapted to receive a key. Upon being received, the key may be rotated in a clockwise direction to cause an insertion of a latch tongue of the lock into a latch tongue housing thereof whereby the lock is closed and the door is locked. When the lock is closed, a spring maintains the tongue within the housing. Correspondingly, the key may be rotated in a counter clockwise direction to cause a removal of the latch tongue from the housing whereby the lock is opened and the door is unlocked. In the lock of the type described hereinbefore, a flexible piece of cardboard (about the size of a business card) may be forced into the housing against the tongue. The cardboard can then be used to push the tongue against the spring whereby the tongue is removed from the housing. It should be understood that because the cardboard may be used to remove the tongue from the housing, an intruder may easily open the lock.
Accordingly, there is a need for an alarm which is activated when the cardboard is used to push the tongue from the housing.